Installation for the collection of gases emitted by a tiltable converter

ABSTRACT

In an installation for the collection of gases emitted by a tiltable converter which includes an enclosure for the converter connected to a suction duct, a damper for controlling the draught in the suction duct is provided, the damper being controlled in dependence on the difference in pressures inside and outside the enclosure and the orientation of the axis of the converter so that the pressure differential is maintained at one level when the converter is vertical and at another level when the converter is non-vertical.

FIELD OF THE INVENTION

The present invention relates to the collection of the gases and fumesreleased from a converter during the course of its operation.

BACKGROUND

Installations are known in which a converter, which can tilt about ahorizontal axis, is enclosed in an enclosure which surrounds it more orless completely, the enclosure being equipped with doors to enablecharging of the converter and being surmounted by a hood which receivesand sucks in the gases leaving the mouth of the converter when it is inthe vertical position during refining, and which sucks in the fumeswhich are released into the enclosure when the converter is in a slopingposition, for example, during charging operations.

The disadvantage of these known installations is that the gas leavingthe converter in the course of refining, when it is in the verticalposition, which is a gas rich in carbon monoxide and hence combustible,is completely burnt, no means being provided for carrying out collectionwithout combustion.

That has the disadvantage, if it is desired to recover the heat ofcombustion of these gases, of its being necessary immediately to producesteam, of its being necessary to cool hotter gases and of having toextract dust from larger volumes than when collecting withoutcombustion.

It is for this reason that it has already been proposed to connect themouth of the converter when the latter is in the vertical position, tothe suction duct by means of a sleeve which has a possibility oftelescopic movement with respect to the suction duct. When the converteris in the vertical position there is then a substantially airtightconnection between the converter mouth and the suction duct. When theconverter is not in the vertical position the sleeve is raised andconnected in a substantially airtight fashion to the enclosuresurrounding the converter and to the duct for sucking away the gases.

It is in fact to be observed that in view of the large dimensions of aconverter mouth, the temperature of the gases escaping from this mouth,the risks of fouling and spatter to which anything located in theproximity of this spout is exposed, the control of the movement ofmembers of large dimensions which are located in this region, is exposedto mishaps, just as the obtaining of airtightness achieved by bearingsurfaces of large dimensions subject to deformation as a result of thehigh temperatures and fouling is difficult to ensure.

SUMMARY OF THE INVENTION

According to the present invention there is provided an installation forthe collection of gases and fumes emitted by a converter which istiltable about a horizontal axis, the installation comprising anenclosure for receiving the converter and of sufficient dimensions toallow tilting of the converter and to surround the converter over atleast the portion of the converter located above the horizontal planecontaining the axis of tilt, said enclosure being provided with at leastone door and being connected in an airtight manner to a fixed suctionduct which is located above the mouth of the converter when theconverter is vertical, at least a first pressure detector for detectingthe pressure of gases in said enclosure and at least a second pressuredetector for detecting the pressure of gases outside said enclosure,said detectors being connected to a regulator for controlling means foradjusting the draught in said suction duct for maintaining thedifference in the pressures detected by said first and said seconddetectors at a first predetermined value when the converter is in avertical position and at a second predetermined value when the converteris in a non-vertical position.

BRIEF DESCRIPTION OF THE DRAWING

The invention will be more fully understood from the followingdescription of an embodiment thereof, given by way of example only, withreference to the accompanying drawing.

In the drawing the single FIGURE shows diagrammatically an embodiment ofan installation in accordance with the present invention.

DETAILED DESCRIPTION

in the drawing a converter 1 is shown mounted to tilt about trunnions 2carried by two pedestals 3 fixed to the floor 4. An enclosure 5surrounds the converter. This enclosure is shown as being equipped withtwo doors 6 and 7. The enclosure 5 is connected by a removable part 8 toa suction duct 11 which includes a dust-extraction device 12. Seals 9and 10 are provided to make the connection airtight.

A fan 14 mounted in the duct 11 sucks in the gases through a damper 15and expels them into a flare 13. Pressure pick-ups such as pick-up 16,mounted in the removable part 8 which forms an extension of theenclosure, send electrical signals to a regulator 19 which also receivesan electrical signal from a pressure pick-up 17 located outside theenclosure. This regulator 19 also receives an electrical signal whichrepresents a nominal value So or S1 depending upon whether the contactor18 of a switch is energized or not which in turn depends on whether theconverter is in the vertical position or not.

The regulator 19 is designed to maintain the difference between thepressures measured by the pickups 16 and 17 at a value equal to So whenthe contactor 18 is not energized, that is to say, when the converter isin the vertical position. If the pressure at pickup 16 is too great theregulator 19 increases the draught by opening damper 15 and closes thedamper down in the contrary situation.

By adjustment of the value of So the amount of air which enters theenclosure 5 may be controlled and hence the degree of combustion of thegases leaving the converter can be controlled. The selection of asufficiently accurate regulation chain enables a gas to be extracted, ofwhich only a very low percentage is burnt.

When the converter is no longer in the vertical position, the contactor18 is energized and the regulator 19 adjusts the damper so that thepressure drop in the enclosure 5 is equal to S1.

If a sufficiently high value is assigned to S1 it will be possible thento suck in at the maximum rate with maximum draught and make the bestuse of the capacities of the fan for sucking away the fumes which arebeing released in the enclosure.

The removable part 8 may be made integral with the enclosure 5 or withthe duct 11 or even with both since, as has been seen, it remains fixedin position during operation of the converter and there is airtightnessbetween the part 8 and the assembly formed by the enclosure 5 andbetween the part 8 and the duct 11.

However, its mobility facilitates dismantling of the portion of the ductlocated immediately above the converter and enables relative movementsof the enclosure 5 and the duct 11 due to expansion, to be absorbed.

Of course it is possible without departing from the scope of theinvention as defined by the appendent claims to conceive of variants andimprovements in detail as well as to visualize the use of equivalentmeans.

There is thus provided an installation which enables, during refining, acollection of the gases which is effected practically withoutcombustion, and without the need for moving members in order to modifythe way in which the converter mouth, the enclosure which surrounds it,and the suction duct are connected together.

What is claimed is:
 1. An installation for the collection of gases andfumes emitted by a converter which is tiltable about a horizontal axis,the installation comprising:an enclosure for receiving the converter andof sufficient dimensions to allow tilting of the converter and tosurround the converter over at least the portion of the converterlocated above the plane containing the axis of tilt; a door in saidenclosure; a suction duct secured to the enclosure near the top thereof;said duct being secured to said enclosure so as to be located above themouth of the converter when the converter is vertical, the mouth of theconverter being uncovered in the enclosure at all times; a firstpressure detector for detecting the pressure of gases in said enclosurenear the top thereof; a second pressure detector for detecting thepressure of gases outside said enclosure; means for adjusting thedraught in said suction duct; a regulator for controlling said draughtadjusting means; and means connecting said first and second pressuredetectors to said regulator; said regulator being operable to controlsaid draught adjusting means to maintain the difference in the pressuresdetected by said pressure detectors at a first predetermined value whenthe converter is vertical and at a second predetermined valuesubstantially greater than the first value when said converter isnon-vertical such that the draught in the suction duct is then maximumto provide maximum suction in the enclosure.
 2. An installation asclaimed in claim 1, including a removable intermediate part connectingsaid enclosure to said suction duct, airtight seals being arrangedbetween said intermediate part and said suction duct and between saidintermediate part and said enclosure.
 3. An installation as claimed inclaim 1, including switch means which is in a first position when theconverter is in a vertical position and is in a second position when theconverter is in a non-vertical position, and means for supplying firstand second reference signals to said regulator and connected to saidregulator through said switch means.
 4. An installation as claimed inclaim 1, wherein said draught adjustment means comprises a damperarranged in said suction duct.